The ring is around 100 years old , but the natural diamond was cut around late 40s to early 50s. It does not have a gold mark but was tested with nitric acid and a "kee" tester to be 10k solid yellow gold. The ring weighs 1.5 grams. Set at the top is a round 2.8 mm transitional cut round natural diamond with an approx total weight of .20 cts. The ring wears to a size 4.5 and can be resized.